Abstract
The failure of a slope in a phosphate mine by shear-sliding along a clay-filled bedding plane in limestone, and by separation across a tension crack at the back, is back-analysed. The failure cannot be explained using laboratory measured values of the shear strength parameters. In order to simulate field conditions better two 'physical models' of the bedding plane were prepared for testing under triaxial compression. Cylindrical cores with an inclined saw-cut discontinuity were filled with remoulded montmorillonite. It is shown that failure in the models initiates along the contacts between the clay infilling and the limestone boundaries, and not through the clay itself, as would be intuitively expected. Furthermore, it is argued that in the analysis of rock slope stability in general, and particularly in the case of clay-filled discontinuities, the influence of paleo-overburden stress on frictional resistance must be resolved before the appropriate constitutive law can be established for analysis.
Original language | English |
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Pages (from-to) | 263-282 |
Number of pages | 20 |
Journal | Geotechnical and Geological Engineering |
Volume | 15 |
Issue number | 4 |
DOIs | |
State | Published - 1 Jan 1997 |
Keywords
- Back analysis
- Montmorillonite
- Plane failure
- Rock slope stability
- Shear strength
- Stiff clays
ASJC Scopus subject areas
- Architecture
- Geotechnical Engineering and Engineering Geology
- Soil Science
- Geology